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copied!<p>Create wrappers which will return some object instead of ostream& which will handle printing. In your case it will object for printing humand-readable value and object for printing database code. Here's rough example which prints human-readable form and integer form. <code>ostream_enum_wrapper_human</code> class with its operator << is used for printing human-readable form, class <code>ostream_enum_wrapper_int</code> with its << is used for printing integer code. To switch from ostream& to wrapper, operator << (ostream&, wrappertag) is used, which wraps ostream object inside of wrapper and returns wrapped object. So next << operator is called on wrapper object, not on ostream&, and wrapper class knows how to print value.</p> <pre><code>#include <iostream> using namespace std; class ostream_enum_wrapper_human { public: ostream& out; ostream_enum_wrapper_human(std::ostream& _out) : out(_out){} }; class ostream_enum_wrapper_int { public: std::ostream& out; ostream_enum_wrapper_int(std::ostream& _out) : out(_out){} }; enum T{zero,one,two}; struct human_readable{} HumanReadable; ostream_enum_wrapper_human operator << (ostream& out, human_readable){ return ostream_enum_wrapper_human(out); } struct print_int{} PrintInt; ostream_enum_wrapper_int operator << (ostream& out, print_int){ return ostream_enum_wrapper_int(out); } ostream& operator << (ostream_enum_wrapper_human out, T t) { switch(t) { case zero: out.out << "zero"; break; case one: out.out << "one"; break; case two: out.out << "two"; break; } return out.out; } ostream& operator << (ostream_enum_wrapper_int out, T t) { return out.out << static_cast<int>(t); } int main() { cout << HumanReadable << zero << PrintInt << zero << HumanReadable << two; } </code></pre> <p><a href="http://codepad.org/AgTYbvqK" rel="nofollow noreferrer">prints zero0two</a></p>

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